There are known valves for exhaled air and talking devices based upon a membrane vibrating under the action of sonoric waves that are intended for gas masks. The valve for the exhaled air and the talking devices are disposed in the gas masks entirely separated or integrated in a joint body with eccentrically disposed axes. The exhaled valves consist of a membrane that is fastened in the center to the valve seat. These known devices are disclosed in German patent document Nos. DE-OS-2 643 853 and DE-OS-3 446 771.
The disadvantages of these described devices are that they occupy a considerable area of the gas mask; they require a displacement of the talking device or of the valves for the exhaled air with respect to the direction of the exhaled air stream; there is relatively small area and elastically of the valves for the exhaled air; there is a considerable resistance of these valves per area unit; it is necessary to have a considerable volume of harmful space around the amount and nose; there are limited possibilities to obtain a sufficient volume of the physiological chamber between consecutively disposed exhaling valves when there is a need to reach a particularly high degree of protection with regard to strong toxic gases.
It is therefore an object of the invention to avoid or reduce to a minimum the above cited disadvantages in providing a compact valve-talking device occupying a minimal part of the gas mask surface and ensuring a high degree of functional protection from toxic substances, a low resistance to exhalation, the possibility for unhampered talking and a minimal volume of harmful space around the nose and mouth.